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7SR11 & 7SR12 Description Of Operation

Figure 1-51 Logic Diagram: Neutral Overvoltage Element (59N)........................................................................... 50

Figure 1-52 Logic Diagram: Under/Over Frequency Detector (81) ..................................................................... 51

Figure 4-1 Typical AR Sequence with 3 Inst and 1 Delayed trip ............................................................................ 54

Figure 4-2 Basic Auto-Reclose Sequence Diagram............................................................................................... 58

Figure 4-3 Logic Diagram: Circuit Breaker Status.................................................................................................. 60

Figure 4-4 Sequence Diagram: Quick Logic PU/DO Timers (Counter Reset Mode Off) ........................................ 63

Figure 4-5 Logic Diagram: Circuit Breaker Fail Protection (50BF) ......................................................................... 64

Figure 4-6 Logic Diagram: VT Supervision Function (60VTS) ............................................................................... 66

Figure 4-7 Logic Diagram: CT Supervision Function (60CTS) – 7SR11 ................................................................ 67

Figure 4-9 Logic Diagram: CT Supervision Function (60CTS) – 7SR12 ................................................................ 68

Figure 4-10 Logic Diagram: Broken Conductor Function (46BC)........................................................................... 68

Figure 4-11 Logic Diagram: Trip Circuit Supervision Feature (74TCS).................................................................. 69

Figure 4-12 Logic Diagram: Close Circuit Supervision Feature (74CCS) .............................................................. 69

Figure 4-13 Functional Diagram for Harmonic Block Feature (81HBL2)................................................................ 70

Figure 4-14 Energy Direction Convention .............................................................................................................. 73

List of Tables

Table 1-1

7SR11 Ordering Options ................................................................................................................... 8

Table 1-2 7SR12 Ordering Options ................................................................................................................. 11

Table 1-3 Summary of 7SR1 Relay Configurations ......................................................................................... 15

Table 4-1 Operating Mode............................................................................................................................... 75

Symbols and Nomenclature

The following notational and formatting conventions are used within the remainder of this document:

• Setting Menu Location MAIN MENU>SUB-MENU

• Setting: Elem name -Setting

• Setting value: value

• Alternatives: [1st] [2nd] [3rd]